The present invention relates to an apparatus and method for frictional stirring weld for elements to be bonded in which apparatus and method a thermal energy is generated by a friction between a rotary tool and the elements to make the elements plastically deformable, and a stir by the rotary tool causes a connection by the plastic deformation between the elements.
In a prior art frictional stirring weld apparatus as disclosed by JP-A-11-226758 (on pages 5 and 6, and FIGS. 4 and 5), a head holding a rotary tool is not movable in each of attitude and position with respect to elements to be bonded so that the rotary tool is positioned and oriented in such a manner that a pin of the rotary tool is aligned along a boundary between first surfaces of the elements and a shoulder of the rotary tool faces to second surfaces extending radially outward from the first surfaces.